You take a amargo fossil from dusty dunes and super evolve it.
If you meant Saichan, then Mt. Lavaflow in the regular Fossil Fighters. I'm not sure about Fossil Fighters: Champions.
You can find him at bonemoth
Treasure Lake
Petrified Woods
in sea floor cavern
You can find allo in the rainbow canyon
you can find it at hot spring heights
up your but & around the corner
at hot spring heights
well you have to find goobs
Go to Rainbow Canyon (Red) and you should find him.
you beat the game an Battle BBBrigeones people